1 files changed, 14 insertions, 14 deletions

diff --git a/src/chain.h b/src/chain.h
index c5304b7d6f..ef7e6f9554 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -216,14 +216,14 @@ public:
     //! (memory only) Sequential id assigned to distinguish order in which blocks are received.
     int32_t nSequenceId;
 
-    //! (memory only) Maximum nTime in the chain upto and including this block.
+    //! (memory only) Maximum nTime in the chain up to and including this block.
     unsigned int nTimeMax;
 
     void SetNull()
     {
-        phashBlock = NULL;
-        pprev = NULL;
-        pskip = NULL;
+        phashBlock = nullptr;
+        pprev = nullptr;
+        pskip = nullptr;
         nHeight = 0;
         nFile = 0;
         nDataPos = 0;
@@ -247,7 +247,7 @@ public:
         SetNull();
     }
 
-    CBlockIndex(const CBlockHeader& block)
+    explicit CBlockIndex(const CBlockHeader& block)
     {
         SetNull();
 
@@ -437,20 +437,20 @@ private:
     std::vector<CBlockIndex*> vChain;
 
 public:
-    /** Returns the index entry for the genesis block of this chain, or NULL if none. */
+    /** Returns the index entry for the genesis block of this chain, or nullptr if none. */
     CBlockIndex *Genesis() const {
-        return vChain.size() > 0 ? vChain[0] : NULL;
+        return vChain.size() > 0 ? vChain[0] : nullptr;
     }
 
-    /** Returns the index entry for the tip of this chain, or NULL if none. */
+    /** Returns the index entry for the tip of this chain, or nullptr if none. */
     CBlockIndex *Tip() const {
-        return vChain.size() > 0 ? vChain[vChain.size() - 1] : NULL;
+        return vChain.size() > 0 ? vChain[vChain.size() - 1] : nullptr;
     }
 
-    /** Returns the index entry at a particular height in this chain, or NULL if no such height exists. */
+    /** Returns the index entry at a particular height in this chain, or nullptr if no such height exists. */
     CBlockIndex *operator[](int nHeight) const {
         if (nHeight < 0 || nHeight >= (int)vChain.size())
-            return NULL;
+            return nullptr;
         return vChain[nHeight];
     }
 
@@ -465,12 +465,12 @@ public:
         return (*this)[pindex->nHeight] == pindex;
     }
 
-    /** Find the successor of a block in this chain, or NULL if the given index is not found or is the tip. */
+    /** Find the successor of a block in this chain, or nullptr if the given index is not found or is the tip. */
     CBlockIndex *Next(const CBlockIndex *pindex) const {
         if (Contains(pindex))
             return (*this)[pindex->nHeight + 1];
         else
-            return NULL;
+            return nullptr;
     }
 
     /** Return the maximal height in the chain. Is equal to chain.Tip() ? chain.Tip()->nHeight : -1. */
@@ -482,7 +482,7 @@ public:
     void SetTip(CBlockIndex *pindex);
 
     /** Return a CBlockLocator that refers to a block in this chain (by default the tip). */
-    CBlockLocator GetLocator(const CBlockIndex *pindex = NULL) const;
+    CBlockLocator GetLocator(const CBlockIndex *pindex = nullptr) const;
 
     /** Find the last common block between this chain and a block index entry. */
     const CBlockIndex *FindFork(const CBlockIndex *pindex) const;